Channel letters are commonly used to provide signage on buildings, specifically when it is desirable to view the signage at night or from a distance. A common channel letter is constructed of an enclosure that outlines the desired shape, such as the shape of a letter or other alphanumeric character. This enclosure has a substantially flat rear surface for attachment to a building, and more importantly, is designed to house a light source such as an incandescent lamp, fluorescent lighting, or neon lighting. Finally, the front of the enclosure is open and adapted to receive a substantially translucent lens. The lens is commonly tinted and diffuses light emanating from the light source, at least to some extent, and thus provides an illuminated letter or other shape.
The light sources typically used in channel letters, such as fluorescent lighting or neon lighting, provide uniform and bright light typically devoid of hot spots; however, they have a variety of shortcomings. For example, such light sources often have a relatively short life, operate at high voltages, consume large amounts of energy, and/or are fragile. Additionally, with regard to neon lighting, it is both fragile and heavy, primarily due to its supporting infrastructure, making it expensive to package or ship. Moreover, it is extremely awkward to initially handle, install, and/or replace neon lighting.
The recent introduction of lightweight and breakage resistant point light sources, as exemplified by high-intensity light-emitting diodes (LEDs), have shown great promise to those interested in alternate light sources for various illumination devices. LEDs are not only lightweight and resilient, but, when compared to other light sources, have a long life, operate at low voltages, and consume small amounts of energy. Despite these benefits, the attributes of uniformity and brightness have proven to be difficult to produce in illumination devices incorporating LEDs. For example, the lenses often used in channel letters do not sufficiently diffuse the light emanating from each LED to eliminate hot spots. Additionally, LEDs are currently available in only a finite number of colors.
Accordingly, there remains a need in the art for an illumination device for simulating channel letters which satisfactorily addresses these problems.